1. Field of the Invention
The present invention relates generally to a cathode ray tube apparatus used in a display monitor and a television receiver. In particular, the present invention relates to a deflection yoke of the cathode ray tube apparatus.
2. Related Background Art
In order to conduct convergence (color convergence onto a screen) of a cathode ray tube apparatus securely, an auxiliary magnetic field correction part typically is provided for a deflection yoke. For example, it is well known to correct misconvergence by using a ferrite member as a magnetic field correction part to vary a main magnetic field. Such misconvergence may include displacement of colors in a horizontal direction in a left and a right region of the screen and in a vertical direction in an upper and a lower region of the screen, which are called xe2x80x9cXHxe2x80x9d and xe2x80x9cYVxe2x80x9d respectively.
A ferrite member frequently used as a magnetic field correction part typically is held in a holder member, and then the holder member holding the ferrite member is attached to a deflection yoke. FIG. 6 shows an example of the holder member denoted as xe2x80x9c24xe2x80x9d and the ferrite member denoted as xe2x80x9c25xe2x80x9d.
However, due to a low dimensional accuracy of ferrite, displacement of the ferrite member is caused easily when the ferrite member is housed in the holder member. This causes difficulties in arranging the ferrite member in a predetermined position in the conventional construction. Consequently, variations in assembly and in performance of convergence correction occur.
At present, reducing the cost of the respective parts constituting a cathode ray tube is required strongly. As a condition for reducing the cost of a deflection yoke, variations in assembly should be avoided. As a matter of course, in order to improve properties of the cathode ray tube such as resolution and color purity, it is preferable that there are no substantial variations in the performance of convergence correction. Thus, a technique for housing ferrite as a correction part in a holder member accurately has been required.
Therefore, with the foregoing in mind, it is an object of the present invention to provide a cathode ray tube apparatus of simple construction, which includes a magnetic field correction part in a desired position, wherein reduction of cost and secure convergence correction can be realized.
In order to achieve the above object, a cathode ray tube apparatus of the present invention comprises a cathode ray tube comprising an envelope composed of a panel and a funnel, and a deflection yoke arranged on an outer part of the funnel of the cathode ray tube and having a vertical deflection coil and a horizontal deflection coil for generating a main magnetic field, wherein the deflection yoke includes a holder for housing a magnetic field correction part for varying the main magnetic field, and the magnetic field correction part is fixed and held by a resilient member.
Since the magnetic field correction part in the cathode ray tube apparatus is held by means of resilient deformation of the resilient member, the magnetic field correction part can be held securely. Therefore, the cathode ray tube apparatus has a simple construction and includes the magnetic field correction part in the desired position, thereby reducing cost and correcting convergence securely.
In the cathode ray tube apparatus of the present invention, it is preferable that the holder comprises a support member for supporting the resilient member.
According to this, the resiliently deformed resilient member is supported by the support member, so that the strength of the resilient member can be improved.